This invention relates generally to electric circuit breakers, and more particularly to a method and apparatus for extinguishing an electric arc produced between the electrical contacts of a circuit breaker during the opening operation, as the contacts separate from each other. The present invention is applicable to circuit breakers in which a gaseous extinguishing medium, such as compressed air or sulfur hexafluoride, is used. For sake of simplicity, however, the description of the present invention will be directed toward a compressed air circuit breaker, that is, toward an air-blast circuit breaker.
In conventional air-blast circuit breakers, a relatively high quantity of the gaseous extinguishing medium is required for reliable extinction of the electric arc produced between the electrical contacts during the opening operation of the circuit breaker.
It is an object of this invention to provide a method and apparatus for the reliable extinction of such an electric arc in which a relatively lesser quantity of the gaseous extinguishing medium is required.